In recent years, downsizing and capacity increase of laminated ceramic capacitors as capacitor elements have been dramatically promoted. Generally, an element body portion of a laminated ceramic capacitor is fabricated by: fabricating a mother block by laminating a plurality of ceramic green sheets each having a conductive pattern, which will serve as an internal electrode layer, printed thereon; singulating the mother block into a plurality of bar-like laminate blocks by dividing the mother block in rows; singulating each of the plurality of laminate blocks into a plurality of laminate chips each having a predetermined size, by further dividing the plurality of laminate blocks in columns; and burning the singulated laminate chips. On that occasion, as downsizing and capacity increase of laminated ceramic capacitors described above are promoted, the ceramic green sheet to be laminated and the conductive pattern printed thereon are also being made thinner.
Further, in order to promote downsizing and capacity increase of capacitor elements, it is also effective to increase an area of a portion where internal electrode layers arranged in a laminated state face each other (i.e., an effective area). As a technique for increasing the effective area, Japanese Patent Laying-Open No. 61-248413 and Japanese Patent Laying-Open No. 6-349669 each disclose a technique for narrowing dielectric layers at portions located adjacent to internal electrode layers in a direction perpendicular to a direction connecting a pair of external electrodes (i.e., dielectric layers at portions forming side surfaces where dielectric layers are exposed, of four external surfaces of a laminated ceramic capacitor extending substantially parallel to a lamination direction of the internal electrode layers).
These techniques divide a mother block such that conductive patterns are exposed at a cut surface corresponding to a side surface of a laminate chip, cover the cut surface with a sufficiently thin dielectric material made of, for example, a covering ceramic green sheet, ceramic slurry, or the like, and thereby can narrow the dielectric layers at portions forming the side surfaces of the laminated ceramic capacitor described above.
Generally, a mother block is often divided by so-called push cutting, in which a push-cutting blade is caused to penetrate into the mother block along a dividing plane which is substantially parallel to a lamination direction of ceramic green sheets, along the lamination direction. However, when the push cutting described above is adopted in a case where a ceramic green sheet and a conductive pattern are thinned, a case where the techniques disclosed in Japanese Patent Laying-Open No. 61-248413 and Japanese Patent Laying-Open No. 6-349669 are applied, and the like, there occurs a problem that various defects due to a shear force applied to a mother block tend to be caused at a cut surface thereof.
For example, in the case where a ceramic green sheet is considerably thinned, there occurs a problem that peeling-off tends to be caused at an end portion of the ceramic green sheet due to a shear force applied to the ceramic green sheet, which may cause deterioration in yield and degradation in reliability. Further, in the case where the techniques disclosed in Japanese Patent Laying-Open No. 61-248413 and Japanese Patent Laying-Open No. 6-349669 are applied, there occurs a problem that an end portion of a conductive pattern may deform due to a shear force applied to the conductive pattern, and conductive patterns which originally should not be brought into conduction may come into contact with each other at the cut surface, and as a result, electrical isolation therebetween cannot be ensured, which may cause deterioration in yield and degradation in reliability.
In order to suppress occurrence of these problems, it is effective to cause a push-cutting blade to penetrate in a dividing step along a dividing plane which is substantially parallel to a lamination direction of ceramic green sheets, along a direction perpendicular to the lamination direction. Thereby, a shear force caused by push cutting can be suppressed from being applied to the ceramic green sheets and the conductive patterns along the lamination direction, and occurrence of the problems described above can be effectively prevented.
However, in the step of singulating a mother block into a plurality of bar-like laminate blocks by dividing the mother block in rows, it is difficult to perform the push cutting along the above direction, for convenience of handling. Accordingly, the push cutting along the above direction is adopted in the step of singulating each of the plurality of bar-like laminate blocks into a plurality of laminate chips by dividing the plurality of bar-like laminate blocks in columns.
On the other hand, also in that case, in order to push-cut the plurality of bar-like laminate blocks obtained by dividing the mother block, along the above direction, it is necessary to rotate each of the plurality of bar-like laminate blocks 90° about an axis line, prior to dividing the plurality of bar-like laminate blocks in columns. However, as downsizing of laminated ceramic capacitors is promoted, each of the plurality of bar-like laminate blocks also has a very small shape, and thus it is very difficult in terms of handling to rotate them one by one, resulting in a considerable pressure on manufacturing cost.